Re: [PATCH v2 0/3] Fixes for memmap accounting

From: Pasha Tatashin
Date: Thu Aug 08 2024 - 11:26:28 EST


On Wed, Aug 7, 2024 at 7:00 PM Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
>
> [ add linux-cxl ]
>
> Pasha Tatashin wrote:
> > Memmap accounting provides us with observability of how much memory is
> > used for per-page metadata: i.e. "struct page"'s and "struct page_ext".
> > It also provides with information of how much was allocated using
> > boot allocator (i.e. not part of MemTotal), and how much was allocated
> > using buddy allocated (i.e. part of MemTotal).
> >
> > This small series fixes a few problems that were discovered with the
> > original patch.
> >
> > v1: https://lore.kernel.org/all/20240806221454.1971755-1-pasha.tatashin@xxxxxxxxxx
> > Changes:
> > - Added patch "mm: don't account memmap on failure"
> > - Changed from using nid in hot-remove functions to non-pernode
> > system-wide accounting for memmap data.
> >
> > Pasha Tatashin (3):
> > mm: update the memmap stat before page is freed
> > mm: don't account memmap on failure
> > mm: don't account memmap per node
>
> Hi Pasha,
>
> Thanks for jumping on this debug!
>
> We almost missed these. Can you update your scripts to auto-cc folks on the
> Reported-by line, and optionally include the lists where the report originated
> next time?

Thank you, I will add them.

>
> This is looking good from my tests, you can add:
>
> Tested-by: Dan Williams <dan.j.williams@xxxxxxxxx>

Thank you for testing

>
> ...but I still want to take a look at some of the implementation choices.

I am about to send v3.

Pasha